1. Field of the Invention
The present invention relates to infusion sets and, in particular, to infusion sets having a cannula which is inserted into the skin of a patient to facilitate the subcutaneous transfer of an infusant.
2. Description of Related Art
Infusion sets are typically used for delivering a fluid, drug or other infusant to a subcutaneous location in a patient. While most infusion sets include a delivery tube connected to an infusion pump or other fluid or drug delivering device, the configuration of some infusion sets have been disadvantageous to patients for a variety of reasons.
If an infusion set includes a base portion disposed on the skin of a patient and a connector portion that attaches to the base portion, a delivery tube may be attached to the connector portion. Thus, when the connector portion is attached to the base portion, the delivery tube may be connected to an infusion pump or other device for fluid delivery, permitting the patient to administer the desired or necessary infusant. However, if the connector portion of the infusion set is positioned in such a manner that the delivery tube is in a position that is undesirable or impractical for the patient, the patient is resigned to removing the base portion from the patient's skin and inserting a new infusion set base, since the old one cannot be safely reused. It is not normally possible to re-orient the base portion because re-orienting the base portion typically includes re-inserting a needle into the skin. Also, re-orienting the base portion can be discomforting, painful or could lead to infection and thus is undesirable for the patient.
Some infusion sets are configured so that the connector portion and, thus, the delivery tube, may rotate freely about the base portion. Freely rotating infusion sets have disadvantages. Generally, too much movement of the delivery tube is undesirable. For example, because the delivery tube is typically delivering a fluid or some type of drug or infusant to a patient, it is necessary that the fluid path remain unobstructed. If the delivery tube is permitted to rotate freely around the base portion of the infusion set, the delivery tube may be subject to entanglement, twisting, kinking or the like, interrupting the infusion process. In addition, a freely rotating delivery tube can, at times, appear or feel to the patient to be disconnected from the patient and, thus, may result in a sense of insecurity for the patient.
The needs of patients who rely on infusion sets are numerous. For example, patients need infusion sets that require a positive action for releasing a connector from a base—infusion sets that release inadvertently are inconvenient and worrisome. In addition, while it is desirable that the size of the infusion set be minimized, it is also desirable that a patient be able to hold on to the infusion set and that protective pieces of the infusion set remain in place when the infusion set is in storage. Moreover, patients desire the flexibility to attach a connector to a base in multiple positions but also a connector that maintains the position of a delivery tube so that the aforementioned problems of a freely rotating tube are avoided.